Eastern Black Swallowtail Caterpillars And Chrysalis

April 21, 2011

I have some pictures of Eastern Black Swallowtails that I wanted to share.

Before I get to that, I wanted to share some information and see if others might have noticed the same thing.

We’ve had quite a few eggs and Caterpillars from the Eastern Black Swallowtail, but just as the Caterpillars get to be a decent size, they disappear. I now have a theory. I think the Green Anoles have been eating them. I offer that theory for a couple of reasons. One, those Anoles have been really stalking our outdoor Butterfly Enclosure that contain the Monarch Butterfly Caterpillars and Chrysalises. I’ve pretty much “Lizard-Proofed” the enclosure, but they haven’t stopped trying to find a way in. My second reason for this theory, is that the Green Anoles were hanging around the Fennel and Dill where the eggs and Caterpillars were feeding until I took them inside to raise them.

So what do you think? Have you ever observed Green Anoles feeding on Butterfly Caterpillars?

Now for the pictures.

This first picture contains two Eastern Black Swallowtail Caterpillars. You can see the one on the left is absolutely huge! I thought for sure it would begin forming a Chrysalis yesterday, but it continues to feed. It almost looks like it’s about to burst.

Two Eastern Black Swallowtail Caterpillars Feeding On Fennel

In comparison to Monarch Caterpillars, the Eastern Black Swallowtail tends to prefer structures where it can attach itself to a structure and hang. This wire structure that the Caterpillar and Chrysalis are attached to is at the bottom of our indoor Butterfly Enclosure. They didn’t attach themselves to the top of the enclosure like a Monarch would typically do. It doesn’t seem to be as concerned about protecting itself from the elements like a Monarch Caterpillar. The only problem with these Eastern Black Swallowtails attaching themselves to this location is there is no way they could exit the Chrysalis and dry their wings without us moving the structure as it’s barely an inch off of the ground.

If you’ve ever wondered what an Eastern Black Swallowtail Chrysalis and Caterpillar look like side by side, well here’s a picture. It’s pretty obvious how difficult it would be to find the Chrysalis in the outdoors. It would likely attach itself to the stem of a plant that matched the color and texture of the Chrysalis and unless you have “eagle eyes” it would be difficult to find.